If you want power for it's own sake, then what is it that you actually want? To feel less insecure, perhaps? I can only see power as a secondary goal, a means to some other end. ENTJs are often type 8s on the Enneagram. 8s, 5s, and 2s are power seekers. We all have some key motivations that don't look too pretty on their own, especially in the beginning of life, but once a person has broken free of the negative aspects of it they move into a healthy and beautiful way of living. (Ideally.)
I think you'd have more fun studying the Enneagram in regards to this question, because there could be type 9 ENTJs or type 8 ENTJs and they'd have very different motivations. 8 - Enneagram Type Eight: The Challenger My apologies if I'm just taking up space and you already know about this or don't care! I'm still hitting the submit button, anyway.